Recording neural waveforms from many implanted microelectrodes in freely behaving animals is a difficult task for most neurophysiologists. While preamplifier head stages solve most electrical problems, multi-wire cabling to post-amplifiers causes significant mechanical problems for freely behaving small animals such as mice, birds, insects and fish. To eliminate the cabling, a 32-channel telemeter for neural waveform recording will be developed, evaluated and marketed. During Phase-I, a prototype 8-channel telemeter will be developed and evaluated. The innovative part of the proposed telemeter is the integrated circuit encoder that enables this technology. This encoder will input neural waveforms from 8 microelectrodes and will output a single pulse stream of encoded data. It will require less than 80microA at 2.5 volts to achieve a 10kHz bandwidth per channel with less than 3microVms noise. Phase-I data transmission will be by optical techniques. Telemeter power will be provided optionally by miniature hearing aid batteries or photodiode arrays. Phase-II will expand the channel capacity to 32, incorporating suggestions and criticisms from the collaborating neurophysiology laboratories. Power and data transmission options will be expanded to include radio-frequency methods. System components and fabrication techniques will be improved to minimize cost and facilitate distribution of the technology. PROPOSED COMMERCIAL APPLICATION: When developed, this instrumentation should be marketable to all neurophysiology laboratories that currently make electro-physiological recordings. In particular it will fill the technology need for long term recording from multielectrode arrays in freely behaving small animals. This instrumentation would also be marketable for neurophysiology teaching. In the long term, this technology may lead to neuroprosthetic devices for clinical applications in spinal cord injury.